Chinese authorities have banned activists and experts from holding a multinational conference in southern China on the legal rights of people infected with HIV, the virus that causes AIDS. As Daniel Schearf reports from Beijing, although Chinese officials have become more supportive of AIDS prevention efforts, discrimination against people with HIV is common, and authorities are still suspicious of activists.

The conference was to bring together Chinese and foreign activists this week in the southern city of Guangzhou to discuss AIDS discrimination. They also were to consider establishing a legal aid center in China for people with HIV and the activists who support them.

Fifty participants from South Africa, India, Thailand, and Canada had planned to attend.

But on Thursday authorities told organizers the conference would not be allowed.

Asia Catalyst, a New York organization that works with activists in Asia to promote human rights, social justice and environmental protection, co-organized the conference. Its partner was China Orchid AIDS Projects in Beijing.

"We were contacted by authorities, who told us that the combination of AIDS and law and foreigners was too sensitive and that the meeting had to be canceled," Sara Davis, the founder and director of Asia Catalyst.

China has in recent years moved from officially denying having an HIV problem to supporting AIDS education and prevention campaigns.

Last year, China outlawed discrimination against people with HIV or AIDS. Officials have also promised anonymous testing and free treatment for poor people infected with the disease.

But AIDS activists are still harassed, and Davis says discrimination remains common.

"If their identity becomes known they risk being evicted from their homes, they lose their jobs, their children are refused access to education, are turned away from schools, and perhaps worst of all are often refused treatment from hospital workers," said Davis.

Davis says a legal aid center is needed to help people infected with HIV when their rights are violated.

She says despite the canceled conference, she is optimistic her group will be able to continue working with Chinese AIDS activists.

However, Chinese authorities have recently shown less tolerance for foreign activists who support the work of Chinese groups.

Earlier this month officials ordered the closure of China Development Brief, a well-respected publication run by a British national that reported on China's social development and civic activity.